Jonathan Haidt (in his 2001 "The Emotional Dog and Its Rational Tail") suggests that (1) “moral discussions and arguments are notorious for the rarity with which persuasion takes place” (p. 819).

(He also claims that (2) “moral positions always have an affective component to them”. Based on these two claims, he hypothesizes that (C) “reasoned persuasion works not by providing logically compelling arguments but by triggering new affectively valenced intuitions in the listener” (p. 819).)

Do you know of any empirical evidence for these premise claims, (1) or (2)? I'm particularly interested in evidence supporting (1).